Agree the figures don't add up...in 11 years I can only think of three 'fires' one of which was told to me second hand and the other two I personally experienced with a HF aerial ablaze on the ground just prior to taxi and a CSDU cooling fan rubbing on it's casing whilst lining up...Plenty of fumes from which not one did we come home early for...the source was always identified and isolated or it just went away...
If I remember correctly the sandwich toaster device was a major source of under floor warnings due to were it vented it's cooking fumes...